Systems that enable electric weapons to be controlled by detecting the presence of a cartridge in a chamber, wherein said systems provide means to, through a supply voltage, determine the impedance of the cartridge in two possible states of the system, when there is no cartridge in the chamber and when there is a cartridge in the chamber, making use of two electrodes, are known in the state of the art.
Among the previous systems is the one described in U.S. Pat. No. 5,755,056A, relating to an electronic weapon and process for controlling said weapon, wherein electrodes are positioned to electrically contact with conductive portions of a round of ammunition within the chamber, voltage supply means for at least one of the electrodes, means for measuring the resistance between the electrodes and means for comparing the measured resistance to at least one reference.
The system described in the aforementioned patent comprises a comparator circuit to detect the presence of a cartridge, and specifically to detect ammunition that can be electrically fired. The circuit is formed by the contacts between the electrodes and a cartridge. If the cartridge is between the two electrodes, the current will be transmitted from one of the electrodes, which can be a firing pin, through the cartridge, to the second electrode, which can be the barrel of the weapon.
However, the measurement of the impedance may be affected by the presence of the user, since the measurement may be distorted depending on whether or not the user makes contact with the metallic parts of the weapon.
The international application WO2016113455A1, by the same applicant of the present application, which describes a cartridge-in-chamber detection system for weapons wherein a microprocessor, by means of a sensor circuit, detects the capacitive variation between the situation in which at least one electrical contact is electrically connected to at least the metallic parts of the weapon and the cartridge, and the situation in which the at least one electrical contact is not electrically connected to at least the metallic parts of the weapon and the cartridge, thereby allowing the presence or absence, respectively, of the cartridge in the chamber to be determined, is also known.
In the aforementioned system, the electrical contact associated with the capacity variation is in electrical contact with the cartridge and the metallic parts of the weapon in contact with the cartridge when said cartridge is in the chamber, which makes it so that in situations in which the cartridge is defective, for example when the metallic rim of the same has been dented during the handling thereof, the absence cartridge in the chamber is erroneously determined, when in fact the cartridge is in the same.
The cartridge-in-chamber detection system for weapons of the present invention has a configuration that solves all of the aforementioned drawbacks, providing a system that does not depend on the presence of defects in the cartridge of the weapon.